1. Field of the Invention
This invention relates to medical devices, and more particularly to a low profile infusion set for intermittent or continuous subcutaneous administration of medication or other substances beneficial to health.
2. Description of the Related Art
Frequent or continuous subcutaneous injection of medication is often accomplished through the use of an infusion set or injection port which may remain in place for several days. In the case of frequent injections, this reduces the need to constantly puncture the skin and thereby reduce the chance of infection and the formation of scar tissue. For continuous subcutaneous delivery of medication such as commonly used with portable insulin pumps, an infusion set is often used to provide a method of temporarily detaching the pump and fluid line for activities such as dressing or bathing. It is also desirable in this instance to detach the fluid line from the pump as close to the injection site as possible leaving a relatively small component attached to body to minimize the interference during dressing, bathing or other activities.
While devices for this purpose have been proposed, these devices have limitations making them less than ideal in practice. By way of example, U.S. Pat. No. 4,755,173 issued to Konopka et al. on Jul. 5, 1988, discloses a soft cannula subcutaneous injection set that relies on a length of tubing with a separate fluid connector for detachment from the source of medication. No provision is provided for disconnecting the fluid tubing from the injection site. The tubing must either be secured to the body with additional adhesive tape or left to awkwardly hang from the injection site where it has a tendency to snag on clothing.
U.S. Pat. No. 5,545,143 issued to Fischell on Aug. 3, 1996, describes a device for the subcutaneous delivery of medication. This device includes a short tubular extension with a connector to the main body of the device which eliminates the tubing but makes the overall package long and somewhat bulky.
U.S. Pat. No. 5,522,803 issued to Teissen-Simony on Jun. 4, 1996, discloses an infusion set that overcomes some of the problems with the other devices but presents it""s own disadvantages. Namely, the infusion needle is not covered for protection against accidental needle sticks or contamination. Also, the cannula housing and needle hub are difficult to align and connect without being directly viewed by the user. This is especially a problem for diabetics with impaired vision. In addition, the guide pins and locking pins of this patent form multiple sharp projecting points which are susceptible to bending or breakage or accidentally poking the user, especially when connecting to injection sites not in the user""s direct line of sight.
U.S. Pat. No. 6,056,715 issued to Funderburk et al. on May 2, 2000, discloses an infusion set that is similar to U.S. Pat. No. 5,522,803 and has some of the same problems and disadvantages, particularly in respect to alignment and use of the latch arms and locking fingers which must bend and are susceptible to breaking.
According to one embodiment of the invention, an infusion set comprises a cannula housing adapted for mounting onto a person""s skin and a needle housing for connection to the cannula housing. The cannula housing has a locking element positioned thereon. A cannula is connected to the cannula housing and extends therefrom. The needle housing has at least a first flexible sidewall and a resilient band connected to the sidewall for deformation upon deflection of the sidewall. The resilient band is lockably engageable with the locking element to thereby secure the housings together, and is releasable from the locking element upon deflection of the sidewall to thereby deform the resilient band out of locking engagement with the locking element. A hollow needle extends through the needle housing for delivering fluid to the cannula from a fluid source.
According to a further embodiment of the invention, an infusion set comprises a cannula housing adapted for mounting onto a patient""s skin and a needle housing adapted for connection to the cannula housing. A cannula is connected to the cannula housing and extends therefrom. A hollow needle for delivering fluid to the cannula from a fluid source extends from a main body of the needle housing such that a distal end of the hollow needle is spaced from the main body. The needle housing further has first and second sidewalls and an upper wall that extends from the main body beyond the distal end of the hollow needle to thereby prevent inadvertent contact of the hollow needle with contaminated surfaces when the needle housing is separated from the cannula housing.
Other objects and advantages of the invention will become apparent upon review of the following detailed description and appended claims, with reference to the accompanying drawings.